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1. Field of the Invention
This invention is related to the field of aviation dealing with military attack aircraft.
The aim of this invention is to provide an airplane that has higher chance of surviving attacks from anti-aircraft weapons when flying over enemy territory than airplanes currently in use. The airplane according to this invention is fitted with a mechanism that enables the airplane to travel in a continuous spiralling motion while flying over enemy teritorry, without the need for the pilot to make continues control adjustments. The mechanism is such that once activated, the spiralling motion is automatic. The mechansim can aslo be dis-engaged by the pilot when so desired. The spiralling motion is achieved during flight without rolling the airplane.
While a pilot flying a conventional airplane such as a jet fighter could make the conventional airplane fly in a spiralling motion, this could only be achieved if the pilot kept making continuous control changes with his own arm. This could become quite tiresome and strenuous after a while and would require continued concentration, if the spiralling was achieved without rolling the airplane. Rolling the airplane, as in the form of a barrel roll, may seem like an easy alternative, but continuous rolling would make the pilot disey after a while, leading to loss of control, and if close to the ground, a potential for a crash. A continuous rolling motion would also make it hard for the pilot to observe enemy territory, navigate and make target selection. That is, using a sustained rolling motion in order to achieve a prolonged spiralling motion would not be practical.
The airplane in this invention would allow the pilot to operate conventional controls in a conventional manner, as when flying in a smooth manner, while the airplane continued to travel in a spiralling motion. The advantage of this is that the pilot would be able to continue to observe enemy territory and would be free to concentrate on targeting enemy sites while the airplane flew in an evasive manner.
2. Description of the Related Art
U.S. Pat. No. 5,322,243 in the name of Stoy shows a missile with variable pitch fins on a rotatable tube that are moved by independent actuators, and a computer to control the operation of the actuators. While the intention of Stoy wasn""t to provide a missile that could travel in a continuous spiralling motion, such a motion could be achieved by the missile shown in Stoy""s patent with appropriate programming of the controlling computer. The current invention provides a mechanical means for inducing a spiralling motion in an airplane that does not need a computer to control the position of the fins on a rotatable tube to induce a spiralling motion in the airplane.
In this invention the spiralling motion of a fast flying airplane is achieved by using moveable fins on a rotatable tube, with the tube encircling a part of the airplane (preferrably the forward part of the fuselage) and able to rotate around the encircled part of the airplane.
The fins are attached to the rotatable tube so that they can be rotated in a pivoting manner relative to the rotatable tube. That is, if the rotatable tube was kept in a fixed position on the airplane so as not to rotate, the fin movement would resemble the movement of canards on airplane such as the Eurofighter and the recent version of the Sukhoi Su-30. The fins would turn in a pitch altering motion in the same direction. With the fins horizontal, the airplane would be allowed to fly smoothly. When the fins are rotated from the horizontal position, they would act to push the airplane in a similar manner to the way that canards would (if positioned on the forward part of the fuselage).
For the airplane to enter a spiralling motion, the fins would need to revolve around the body of the airplane so that the airplane is pushed in changing directions. In the invention this achieved by using the rotatable tube, that allows the fins to revolve around the fuselage of the airplanexe2x80x94using the rotatable tube as means of travelling around a part of the fuselage of the airplane. The invention provides a number of means by which rotation of the rotatable tube can be achieved. One way is to use fins that are of unequal size with respect to one another. Having fins that are of unequal size would cause an aerodynamic imbalance when the fins are moved from the horizontal position. With one fin pushing harder than the other, rotation of rotatable tube would result. The rotation of the rotatable tube would be automatic and continuous while the imbalance between the fins was maintained. Placing the fins back in a horizontal position would remove the imbalance, allowing the rotatable tube to come to rest. Friction between the airplane and the rotatable tube or a braking mechanism such as a hydraulicly activated brake pad being push against the rotatable tube could help to stop the rotatable tube from rotating.
Another way of causing the rotatable tube to rotate according to the invention is to increase the pitch of one fin more than that of the other. Increasing the pitch of one fin relative to the other would cause an aerodynamic imbalance on the rotatable tube, thereby forcing it to rotate. Allowing the fins to return to a horizontal position would remove the aerodynamic imbalance, allowing the rotatable tube to come to rest.
Although the airplane could be in the form of a jet propelled airplane, it could be in the form of any one of a range of airplanes such as turbo-props.